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To be effective, the insulation must be suitable for the voltage used and
conditions such as temperature and other environmental factors like moisture, oil,
gasoline, corrosive fumes, or other substances that could cause the insulator to fail.
2) Guarding involves locating or enclosing electric equipment to make sure

people don't accidentally come into contact with its live parts. Effective guarding
requires equipment with exposed parts operating at 50 volts or more to be placed
where it is accessible only to authorized people qualified to work with it.
Recommended locations are a room, vault, or similar enclosure; a balcony, gallery, or
elevated platform; or a site elevated 8 feet (2.44 meters) or more above the floor.
Sturdy, permanent screens also can serve as effective guards.
Conspicuous signs must be posted at the entrances to electrical rooms and
similarly guarded locations to alert people to the electrical hazard and to forbid entry
to unauthorized people. Signs may contain the word “Danger”, “Warning” or
“Caution” and beneath that, appropriate concise wording that alerts people to the
hazard or gives an instruction, such as “Danger/High Voltage/Keep Out” (Figure
14.7).

Figure 14.7 – Electrical Safety signs

3) Grounding a tool or electrical system means intentionally creating a low-
resistance path that connects to the earth. This prevents the buildup of voltages that
could cause an electrical accident. Grounding is normally a secondary protective
measure to protect against electric shock. It does not guarantee that you won t get a‟
shock or be injured or killed by an electrical current. It will, however, substantially
reduce the risk, especially when used in combination with other safety measures.
A service or system ground is designed primarily to protect machines, tools,
and insulation against damage. One wire, called the “neutral” or “grounded”

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